Flora of North America species comparison

50-300 cm tall, 2-4 mm thick, often compressed, erect or ascending, hard, becoming almost woody;

nodes swollen, glabrous or pubescent;

internodes glabrous, glaucous.

100-300 cm tall, 4-10 mm thick, decumbent, semi-woody at the base, simple or branching from the middle nodes, prophylls prominent, to 15 cm;

nodes contracted, pilose, sericeous;

internodes glabrous or with papillose-based hairs below the nodes.

not keeled, shorter than or equal to the internodes, glabrous or the lower sheaths at least partially pubescent, hairs papillose-based;

ligules 0.3-1.5 mm;

blades 10-60 cm long, 3-20 mm wide, elongate, flat, abaxial surfaces and margins scabrous, adaxial surfaces occasionally pubescent near the base, with prominent, white midveins, bases rounded to narrowed.

shorter or longer than the internodes, rounded, sparsely hispid, hairs papillose-based, thick, fragile, penetrating and irritating the skin when handled, margins glabrous or ciliate;

collars more densely pubescent than the sheaths, hairs papillose-based;

ligules 1.5-2 mm, with longer hairs immediately behind, growing from the base of the blades;

blades 20-50 cm long, 15-40 mm wide, spreading, flat or with involute margins, bases subcordate to cordate, margins glabrous or sparsely hairy.

10-45 cm, to 1/2 as wide as long, open or somewhat contracted, with many spikelets;

branches 4-12 cm, opposite or alternate, ascending to spreading;

pedicels 0.3-2.5 mm, scabridulous to scabrous, appressed to diverging less than 45° from the branch axes.

terminal, 25-45 cm long, 5-15 cm wide, lax, contracted to diffuse, not breaking at the base and becoming tumbleweeds, all or most secondary branches confined to the distal 1/3;

lower branches whorled;

pedicels 0.5-2 mm, appressed.

2.4-3.4 mm long, 1-1.3 mm wide, ellipsoid-lanceoloid to narrowly ovoid, often purplish, glabrous, acute.

1.8-2.5 mm long, 0.5-1 mm wide, narrowly ellipsoid, glabrous.

1.4-2.2 mm, 1/3 – 1/2 as long as the spikelets, 3-5-veined, obtuse;

upper glumes and lower lemmas subequal, glabrous, 5-9-veined, margins scarious, acute;

lower florets staminate;

upper florets 1.8-2.8 mm long, 0.9-1.1 mm wide, smooth, lustrous, acute.

0.7-1.4 mm, about 1/2 as long as the spikelets, 3-5-veined, acute to attenuate;

upper glumes and lower lemmas subequal, about as long as the spikelets, 7-11-veined;

lower florets sterile;

lower paleas 1.3-1.7 mm;

upper florets 1.2-1.6 mm long, 0.5-0.7 mm wide, glabrous, smooth, shiny, chestnut brown to dark brown.

= 18, 36.

= 36.